Linux: >> Linux Kernel >> 6.1.49 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
f2fs: use global inline_xattr_slab instead of per-sb slab cache
As Hong Yun reported in mailing list:
loop7: detected capacity change from 0 to 131072
------------[ cut here ]------------
kmem_cache of name 'f2fs_xattr_entry-7:7' already exists
WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 kmem_cache_sanity_check mm/slab_common.c:109 [inline]
WARNING: CPU: 0 PID: 24426 at mm/slab_common.c:110 __kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307
CPU: 0 UID: 0 PID: 24426 Comm: syz.7.1370 Not tainted 6.17.0-rc4 #1 PREEMPT(full)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
RIP: 0010:kmem_cache_sanity_check mm/slab_common.c:109 [inline]
RIP: 0010:__kmem_cache_create_args+0xa6/0x320 mm/slab_common.c:307
Call Trace:
__kmem_cache_create include/linux/slab.h:353 [inline]
f2fs_kmem_cache_create fs/f2fs/f2fs.h:2943 [inline]
f2fs_init_xattr_caches+0xa5/0xe0 fs/f2fs/xattr.c:843
f2fs_fill_super+0x1645/0x2620 fs/f2fs/super.c:4918
get_tree_bdev_flags+0x1fb/0x260 fs/super.c:1692
vfs_get_tree+0x43/0x140 fs/super.c:1815
do_new_mount+0x201/0x550 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x298/0x2f0 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x8e/0x3a0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
The bug can be reproduced w/ below scripts:
- mount /dev/vdb /mnt1
- mount /dev/vdc /mnt2
- umount /mnt1
- mounnt /dev/vdb /mnt1
The reason is if we created two slab caches, named f2fs_xattr_entry-7:3
and f2fs_xattr_entry-7:7, and they have the same slab size. Actually,
slab system will only create one slab cache core structure which has
slab name of "f2fs_xattr_entry-7:3", and two slab caches share the same
structure and cache address.
So, if we destroy f2fs_xattr_entry-7:3 cache w/ cache address, it will
decrease reference count of slab cache, rather than release slab cache
entirely, since there is one more user has referenced the cache.
Then, if we try to create slab cache w/ name "f2fs_xattr_entry-7:3" again,
slab system will find that there is existed cache which has the same name
and trigger the warning.
Let's changes to use global inline_xattr_slab instead of per-sb slab cache
for fixing.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: Handle incorrect num_connectors capability
The UCSI spec states that the num_connectors field is 7 bits, and the
8th bit is reserved and should be set to zero.
Some buggy FW has been known to set this bit, and it can lead to a
system not booting.
Flag that the FW is not behaving correctly, and auto-fix the value
so that the system boots correctly.
Found on Lenovo P1 G8 during Linux enablement program. The FW will
be fixed, but seemed worth addressing in case it hit platforms that
aren't officially Linux supported.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
MIPS: ftrace: Fix memory corruption when kernel is located beyond 32 bits
Since commit e424054000878 ("MIPS: Tracing: Reduce the overhead of
dynamic Function Tracer"), the macro UASM_i_LA_mostly has been used,
and this macro can generate more than 2 instructions. At the same
time, the code in ftrace assumes that no more than 2 instructions can
be generated, which is why it stores them in an int[2] array. However,
as previously noted, the macro UASM_i_LA_mostly (and now UASM_i_LA)
causes a buffer overflow when _mcount is beyond 32 bits. This leads to
corruption of the variables located in the __read_mostly section.
This corruption was observed because the variable
__cpu_primary_thread_mask was corrupted, causing a hang very early
during boot.
This fix prevents the corruption by avoiding the generation of
instructions if they could exceed 2 instructions in
length. Fortunately, insn_la_mcount is only used if the instrumented
code is located outside the kernel code section, so dynamic ftrace can
still be used, albeit in a more limited scope. This is still
preferable to corrupting memory and/or crashing the kernel.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-14
In the Linux kernel, the following vulnerability has been resolved:
e1000: fix OOB in e1000_tbi_should_accept()
In e1000_tbi_should_accept() we read the last byte of the frame via
'data[length - 1]' to evaluate the TBI workaround. If the descriptor-
reported length is zero or larger than the actual RX buffer size, this
read goes out of bounds and can hit unrelated slab objects. The issue
is observed from the NAPI receive path (e1000_clean_rx_irq):
==================================================================
BUG: KASAN: slab-out-of-bounds in e1000_tbi_should_accept+0x610/0x790
Read of size 1 at addr ffff888014114e54 by task sshd/363
CPU: 0 PID: 363 Comm: sshd Not tainted 5.18.0-rc1 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
<IRQ>
dump_stack_lvl+0x5a/0x74
print_address_description+0x7b/0x440
print_report+0x101/0x200
kasan_report+0xc1/0xf0
e1000_tbi_should_accept+0x610/0x790
e1000_clean_rx_irq+0xa8c/0x1110
e1000_clean+0xde2/0x3c10
__napi_poll+0x98/0x380
net_rx_action+0x491/0xa20
__do_softirq+0x2c9/0x61d
do_softirq+0xd1/0x120
</IRQ>
<TASK>
__local_bh_enable_ip+0xfe/0x130
ip_finish_output2+0x7d5/0xb00
__ip_queue_xmit+0xe24/0x1ab0
__tcp_transmit_skb+0x1bcb/0x3340
tcp_write_xmit+0x175d/0x6bd0
__tcp_push_pending_frames+0x7b/0x280
tcp_sendmsg_locked+0x2e4f/0x32d0
tcp_sendmsg+0x24/0x40
sock_write_iter+0x322/0x430
vfs_write+0x56c/0xa60
ksys_write+0xd1/0x190
do_syscall_64+0x43/0x90
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f511b476b10
Code: 73 01 c3 48 8b 0d 88 d3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 2b 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 8e 9b 01 00 48 89 04 24
RSP: 002b:00007ffc9211d4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000004024 RCX: 00007f511b476b10
RDX: 0000000000004024 RSI: 0000559a9385962c RDI: 0000000000000003
RBP: 0000559a9383a400 R08: fffffffffffffff0 R09: 0000000000004f00
R10: 0000000000000070 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc9211d57f R14: 0000559a9347bde7 R15: 0000000000000003
</TASK>
Allocated by task 1:
__kasan_krealloc+0x131/0x1c0
krealloc+0x90/0xc0
add_sysfs_param+0xcb/0x8a0
kernel_add_sysfs_param+0x81/0xd4
param_sysfs_builtin+0x138/0x1a6
param_sysfs_init+0x57/0x5b
do_one_initcall+0x104/0x250
do_initcall_level+0x102/0x132
do_initcalls+0x46/0x74
kernel_init_freeable+0x28f/0x393
kernel_init+0x14/0x1a0
ret_from_fork+0x22/0x30
The buggy address belongs to the object at ffff888014114000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1620 bytes to the right of
2048-byte region [ffff888014114000, ffff888014114800]
The buggy address belongs to the physical page:
page:ffffea0000504400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14110
head:ffffea0000504400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x100000000010200(slab|head|node=0|zone=1)
raw: 0100000000010200 0000000000000000 dead000000000001 ffff888013442000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
==================================================================
This happens because the TBI check unconditionally dereferences the last
byte without validating the reported length first:
u8 last_byte = *(data + length - 1);
Fix by rejecting the frame early if the length is zero, or if it exceeds
adapter->rx_buffer_len. This preserves the TBI workaround semantics for
valid frames and prevents touching memory beyond the RX buffer.
CVSS Score
7.1
EPSS Score
0.0
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
net: usb: asix: validate PHY address before use
The ASIX driver reads the PHY address from the USB device via
asix_read_phy_addr(). A malicious or faulty device can return an
invalid address (>= PHY_MAX_ADDR), which causes a warning in
mdiobus_get_phy():
addr 207 out of range
WARNING: drivers/net/phy/mdio_bus.c:76
Validate the PHY address in asix_read_phy_addr() and remove the
now-redundant check in ax88172a.c.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
net: stmmac: fix the crash issue for zero copy XDP_TX action
There is a crash issue when running zero copy XDP_TX action, the crash
log is shown below.
[ 216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000
[ 216.187524] Internal error: Oops: 0000000096000144 [#1] SMP
[ 216.301694] Call trace:
[ 216.304130] dcache_clean_poc+0x20/0x38 (P)
[ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0
[ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400
[ 216.317701] __stmmac_xdp_run_prog+0x164/0x368
[ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00
[ 216.326576] __napi_poll+0x40/0x218
[ 216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt
For XDP_TX action, the xdp_buff is converted to xdp_frame by
xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame
depends on the memory type of the xdp_buff. For page pool based xdp_buff
it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy
XSK pool based xdp_buff it produces xdp_frame with memory type
MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the
memory type and always uses the page pool type, this leads to invalid
mappings and causes the crash. Therefore, check the xdp_buff memory type
in stmmac_xdp_xmit_back() to fix this issue.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
RDMA/core: Check for the presence of LS_NLA_TYPE_DGID correctly
The netlink response for RDMA_NL_LS_OP_IP_RESOLVE should always have a
LS_NLA_TYPE_DGID attribute, it is invalid if it does not.
Use the nl parsing logic properly and call nla_parse_deprecated() to fill
the nlattrs array and then directly index that array to get the data for
the DGID. Just fail if it is NULL.
Remove the for loop searching for the nla, and squash the validation and
parsing into one function.
Fixes an uninitialized read from the stack triggered by userspace if it
does not provide the DGID to a kernel initiated RDMA_NL_LS_OP_IP_RESOLVE
query.
BUG: KMSAN: uninit-value in hex_byte_pack include/linux/hex.h:13 [inline]
BUG: KMSAN: uninit-value in ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
hex_byte_pack include/linux/hex.h:13 [inline]
ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
ip6_addr_string+0x18a/0x3e0 lib/vsprintf.c:1509
ip_addr_string+0x245/0xee0 lib/vsprintf.c:1633
pointer+0xc09/0x1bd0 lib/vsprintf.c:2542
vsnprintf+0xf8a/0x1bd0 lib/vsprintf.c:2930
vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2279
vprintk_emit+0x307/0xcd0 kernel/printk/printk.c:2426
vprintk_default+0x3f/0x50 kernel/printk/printk.c:2465
vprintk+0x36/0x50 kernel/printk/printk_safe.c:82
_printk+0x17e/0x1b0 kernel/printk/printk.c:2475
ib_nl_process_good_ip_rsep drivers/infiniband/core/addr.c:128 [inline]
ib_nl_handle_ip_res_resp+0x963/0x9d0 drivers/infiniband/core/addr.c:141
rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
rdma_nl_rcv+0xefa/0x11c0 drivers/infiniband/core/netlink.c:259
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x333/0x3d0 net/socket.c:729
____sys_sendmsg+0x7e0/0xd80 net/socket.c:2617
___sys_sendmsg+0x271/0x3b0 net/socket.c:2671
__sys_sendmsg+0x1aa/0x300 net/socket.c:2703
__compat_sys_sendmsg net/compat.c:346 [inline]
__do_compat_sys_sendmsg net/compat.c:353 [inline]
__se_compat_sys_sendmsg net/compat.c:350 [inline]
__ia32_compat_sys_sendmsg+0xa4/0x100 net/compat.c:350
ia32_sys_call+0x3f6c/0x4310 arch/x86/include/generated/asm/syscalls_32.h:371
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:3
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
ipv4: Fix reference count leak when using error routes with nexthop objects
When a nexthop object is deleted, it is marked as dead and then
fib_table_flush() is called to flush all the routes that are using the
dead nexthop.
The current logic in fib_table_flush() is to only flush error routes
(e.g., blackhole) when it is called as part of network namespace
dismantle (i.e., with flush_all=true). Therefore, error routes are not
flushed when their nexthop object is deleted:
# ip link add name dummy1 up type dummy
# ip nexthop add id 1 dev dummy1
# ip route add 198.51.100.1/32 nhid 1
# ip route add blackhole 198.51.100.2/32 nhid 1
# ip nexthop del id 1
# ip route show
blackhole 198.51.100.2 nhid 1 dev dummy1
As such, they keep holding a reference on the nexthop object which in
turn holds a reference on the nexthop device, resulting in a reference
count leak:
# ip link del dev dummy1
[ 70.516258] unregister_netdevice: waiting for dummy1 to become free. Usage count = 2
Fix by flushing error routes when their nexthop is marked as dead.
IPv6 does not suffer from this problem.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
ip6_gre: make ip6gre_header() robust
Over the years, syzbot found many ways to crash the kernel
in ip6gre_header() [1].
This involves team or bonding drivers ability to dynamically
change their dev->needed_headroom and/or dev->hard_header_len
In this particular crash mld_newpack() allocated an skb
with a too small reserve/headroom, and by the time mld_sendpack()
was called, syzbot managed to attach an ip6gre device.
[1]
skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8 tail:0x70 end:0x6c0 dev:team0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:213 !
<TASK>
skb_under_panic net/core/skbuff.c:223 [inline]
skb_push+0xc3/0xe0 net/core/skbuff.c:2641
ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371
dev_hard_header include/linux/netdevice.h:3436 [inline]
neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
neigh_output include/net/neighbour.h:556 [inline]
ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136
__ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220
NF_HOOK_COND include/linux/netfilter.h:307 [inline]
ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
mld_send_cr net/ipv6/mcast.c:2154 [inline]
mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-13
In the Linux kernel, the following vulnerability has been resolved:
RDMA/cm: Fix leaking the multicast GID table reference
If the CM ID is destroyed while the CM event for multicast creating is
still queued the cancel_work_sync() will prevent the work from running
which also prevents destroying the ah_attr. This leaks a refcount and
triggers a WARN:
GID entry ref leak for dev syz1 index 2 ref=573
WARNING: CPU: 1 PID: 655 at drivers/infiniband/core/cache.c:809 release_gid_table drivers/infiniband/core/cache.c:806 [inline]
WARNING: CPU: 1 PID: 655 at drivers/infiniband/core/cache.c:809 gid_table_release_one+0x284/0x3cc drivers/infiniband/core/cache.c:886
Destroy the ah_attr after canceling the work, it is safe to call this
twice.
CVSS Score
5.5
EPSS Score
0.0
Published
2026-01-13